So I'm looking at a bf7520 amongst other options. What I'm curious about is the drylight insulation. Is it hard like concrete or is it more of a chalk like drywall compound inside. I realize its poured but is it something that someone is going to need to take a demo hammer to or will it offer no resistance really.

It's in between your examples.  It's hard like concrete (because it is), but it's porous like lava rock.  Although AMSEC will claim it's not a burglary barrier, it's far more of a barrier than gypsum board safe with a single outer wall.  More so towards brute force than by a tool attack.

It will offer no resistance. Once they are through the thin 10ga outer shell, you can chip away the 'insulation' with a screwdriver. Chances are whatever you use to break the outer skin, will have destroyed the drylight inside.

Sounds like resistance to me.  


Let's take a traditional gun safe.  You take a grinder and cut through the outer skin.  This also cuts most of the inner insulation.  Once that outer skin drops, you're either reaching directly into the safe, or simply using your fist to knock out what little remaining gypsum board is in your way and then reaching in.

Take the AMSEC.  You cut the outer skin.  You likely haven't cut most of the insulation due to its depth.  You drop the outer skin.  Then you have to put your grinder, or a screwdriver, or a hammer, into that hole to knock out the remaining insulation.  [Billy Mays]  But Wait!  There's More! [/Billy Mays]  Now you're up against another steel panel that needs to be cut.  And if you're planning on using the same grinder, your exterior hole has to be substantially larger than the interior hole due to the need to get the tool in there.  So now you're back to enlarging the outer hole, eliminating more insulation, and then attacking the inner liner.

So will the safe offer as much resistance as a burglar rated container with a high density fill?  Absolutely not.  Will it offer more resistance than a gypsum lines safe?  Yes.  I can crumble gypsum board in my hand.  I can not do the same with the fill out of the AMSEC.  I reverse engineered that fill a few years ago, and have a test cylinder of it on my desk.  It's much more robust than drywall.